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Membrane sweeping versus dinoprostone vaginal insert in the management of pregnancies beyond 41 weeks with an unfavourable cervix |
Magann E F, Chauhan S P, McNamara M F, Bass J D, Estes C M, Morrison J C |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology Membrane sweeping in the management of pregnancies beyond 42 weeks with an unfavourable cervix.
Type of intervention Treatment and secondary prevention.
Economic study type Cost-effectiveness analysis.
Study population Women in their mid 20s and primarily white, presenting at a gestational age of 41 weeks. The gestational age was confirmed by date of last menstrual period, uterine size on first examination, first auscultation of fetal heart tones, and the ultrasound results before 20 weeks' gestation. Women of uncertain gestational age were not included in the study.
Setting The study was conducted at the University of Mississippi Medical Center, USA.
Dates to which data relate The effectiveness and resource use data were collected between January 1995 and June 1996. The dates of the resource data and the price year were not stated.
Source of effectiveness data The estimates of effectiveness and resources used were derived from a single study.
Link between effectiveness and cost data The costing was undertaken prospectively on the same patient sample as that used in the effectiveness study.
Study sample 182 women with singleton pregnancies, vertex presentation, intact membranes, reassuring antenatal assessment, no contraindication to a vaginal delivery, and a Bishop score of 4 or less who were willing to participate in the study were prospectively randomised to daily membrane sweeping (91 women) or daily dinoprostone vaginal insert (Cervidil) (91 women). A sample size calculation determined that 90 women were sufficient (power of 0.90, alpha of 0.05 and beta of 0.20) in each group to demonstrate a difference of interventions by 18% between the two groups. The number and characteristics of women who declined to participate were not stated.
Study design The study was a single-centre, randomised controlled trial of a total duration of 18 months. The method of randomisation of participants between the two study groups was through drawing a card, generated from a table of random numbers sealed in an opaque envelope. The technique of membrane sweeping involved separation of the membranes from the lower uterine segment with two circumferential sweeps of the examining finger, the cervix was stretched by the examining finger daily until membrane stripping could be accomplished. All patients were examined by one of the two examiners blinded to group assignment to determine the daily Bishop score. Patients were examined on a daily basis until spontaneous labour, rupture of membrane, or a Bishop score of 8 or more occurred (at which time patients were admitted for labour induction), or until 42 weeks were attained, at which time all remaining patients were admitted for labour induction. The patients were followed until delivery. No loss to follow-up was reported.
Analysis of effectiveness The analysis was based on intention to treat. The two groups were shown to be comparable in age, sex and prognostic features. All participants in the study were treated and the analysis was based on the full number of study participants. The effectiveness outcomes reported were the Bishop score, the number of women admitted to labour and delivery in active labour, the number of women having labour induction in 42 weeks, the time interval from admission to delivery, the gestational age on admission, the increase of gestational age from study entrance to admission to labour and delivery, mode of delivery, reason for operative delivery, birth weight, Apgar scores, neonatal disposition, and reasons for admission to newborn intensive care unit.
Effectiveness results The Bishop score on admission to labour and delivery was 8.56 (+/- 2.5) for the membrane sweeping group and 6.63 (+/- 2.55) for the dinoprostone group, (p<0.001).
63 of 91 women (69%) in the membrane sweeping group were admitted to labour and delivery in active labour compared with 44 of 91 (48%) in the dinoprostone group, (p=0.009).
Fewer of the membrane sweeping group, 4 of 91 (9%), had a labour induction at 42 weeks than the dinoprostone group, 13 of 91 (4%), (p=0.041).
The time interval from admission to delivery was 10.8 (+/- 6.9) hours in the membrane sweeping group and 13.3 (+/- 6.7) hours, (p=0.01), in the dinoprostone group.
The gestational age on admission, the increase of gestational age from study entrance to admission to labour and delivery, the mode of delivery, the reason for operative delivery, birth weight, Apgar scores, neonatal disposition, and reasons for admission to newborn intensive care unit were similar for both groups.
Two patients in the cervidil group and one in the membrane-sweeping group developed postpartum endometritis. All three patients had undergone abdominal delivery, had prolonged rupture of membranes, and had a large number of vaginal examinations with rupture of membranes.
Clinical conclusions Daily membrane sweeping appears to be superior to dinoprostone in the management of pregnancies with an unfavourable cervix with greater Bishop scores on admission to labour and delivery, fewer hours from admission to delivery, and fewer labour inductions at 42 weeks.
Measure of benefits used in the economic analysis No summary measure of benefits was used in the economic analysis. The benefits are therefore associated with the effectiveness results reported above. The costs were analysed separately for the two study groups and thus the cost-effectiveness analysis was of a cost-consequences design.
Direct costs Discounting was not relevant because of the short period of follow-up (less than one year). Direct costs included doses of dinoprostone ($120 per dose, total cost $27,480), and nonstress tests and amniotic fluid estimation(AFE) with interpretation ($140 per test, total cost $32,060) which were used in the 91 women in the dinoprostone group. The membrane-sweeping group had antenatal testing twice a week, or a total of 108 tests ($140 per test) at a total cost of $15,120. Intrapartum costs were $26 per hour. The dinoprostone group spent an average of 13.4 hours in labour, while the membrane-sweeping group spent an average of 10.8 hours in labour. Costs and quantities were reported separately. The price year was not given.
Statistical analysis of costs No statistical analysis of costs was performed.
Indirect Costs No indirect costs were evaluated.
Sensitivity analysis No sensitivity analysis was performed.
Estimated benefits used in the economic analysis Not applicable. The reader is referred to the effectiveness results above.
Cost results The total antenatal cost for the dinoprostone group was $59,540 compared with $15,120 for the membrane-sweeping group. Total intrapartum costs were $31,704 for the dinoprostone group and $25,552 for the membrane-sweeping group. Total antepartum and intrapartum costs for the dinoprostone group were $91,244 compared with $40,672 for the membrane-sweeping group.
Synthesis of costs and benefits No synthesis of costs and benefits was performed.
Authors' conclusions Daily membrane sweeping appears to be superior to dinoprostone in the management of pregnancies with an unfavourable cervix at a combined antepartum and intrapartum cost that is less than one-half the cost of using the vaginal insert method.
CRD COMMENTARY - Selection of comparators The author explicitly justified the use of dinoprostone vaginal inserts (Cervidil) as the comparator treatment to dinoprostone gel (Prepidil) by asserting that the vaginal inserts achieve ripening over a shorter period. The author acknowledged that a recent investigation (Doany et al.) suggested that a combined therapy of membrane sweeping and dinoprostone was superior in preventing post-term pregnancies compared to either technique on its own.
Validity of estimate of measure of benefit The analysis was based on a randomised controlled trial and on intention to treat, which was appropriate for the study question. The study sample appeared to be representative of the study population. The patient groups were shown to be comparable at analysis and appropriate statistical analysis was undertaken. The authors did not, however, derive a summary measure of health benefit for the economic analysis. The analysis used a cost-consequences design.
Validity of estimate of costs Only direct medical costs were included in the analysis. All categories of costs relevant to the perspective adopted were included. Costs were reported separately from quantities. However, no statistical analyses of quantities or prices were performed. Although the costs were incurred over a period of 18 months, discounting was not relevant due to the short follow-up period of each patient. The price dates were not reported. Users of this database are advised to consider the costs in their own settings.
Other issues The authors made appropriate comparisons of their findings with those from other studies and the issue of generalisability to other settings was addressed. The authors' conclusions reflect the study scope. The lack of statistical analyses on the resource use and costs makes it difficult to draw conclusions regarding the significance of the cost differences. The lack of a summary benefit measure makes analysis of the overall benefit from the viewpoint of patients difficult.
Implications of the study The study results suggest that membrane sweeping is a cost-effective intervention compared with dinoprostone inserts. Additional research of the cost-effectiveness and cost-utility of combined membrane sweeping and dinoprostone treatment could further inform the most appropriate clinical practice.
Source of funding Supported in part by the Vicksburg Hospital Medical Foundation.
Bibliographic details Magann E F, Chauhan S P, McNamara M F, Bass J D, Estes C M, Morrison J C. Membrane sweeping versus dinoprostone vaginal insert in the management of pregnancies beyond 41 weeks with an unfavourable cervix. Journal of Perinatology 1999; 19(2): 88-91 Other publications of related interest Doany W, McCarty J. Outpatient management of the uncomplicated postdate pregnancy with intravaginal prostaglandin E2 gel and membrane stripping. The Journal of Maternal-Fetal Medicine 1997;6:71-8.
Indexing Status Subject indexing assigned by NLM MeSH Adult; Cervical Ripening; Dinoprostone /therapeutic use; Female; Humans; Oxytocics /therapeutic use; Pregnancy; Pregnancy Outcome; Prospective Studies; Suppositories AccessionNumber 22000006130 Date bibliographic record published 30/09/2001 Date abstract record published 30/09/2001 |
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